Self-consistent ab initio calculations, based on the density functional theory （DFT） and using the full potential linear augmented plane wave （FLAPW） method, are performed to investigate both electronic and magnet...Self-consistent ab initio calculations, based on the density functional theory （DFT） and using the full potential linear augmented plane wave （FLAPW） method, are performed to investigate both electronic and magnetic properties of the MnS layers. Polarized spin and spin-orbit coupling are included in the calculations within the framework of the antiferromagnetic state between two adjacent Mn layers. Magnetic moments considered to lie along axes are computed. Obtained data from ab initio calculations are used as input data for the high temperature series expansion （HTSE） calculations to compute other magnetic parameters. The zero-field high temperature static susceptibility series of the spin-4.39 nearest-neighbour Heisenberg model on centred face cubic （FCC） and lattices is thoroughly analysed by a power series coherent anomaly method （CAM）. The exchange interactions between the magnetic atoms, the N@el temperature, and the critical exponent associated with the magnetic susceptibility are obtained for the MnS layer.展开更多
A new structure containing negative refractive index dielectric layer(NRIDL) is introduced into microcavity. The properties of the new microcavity organic light-emitting devices(MOLEDs) are investigated. In the experi...A new structure containing negative refractive index dielectric layer(NRIDL) is introduced into microcavity. The properties of the new microcavity organic light-emitting devices(MOLEDs) are investigated. In the experiment, the transfer matrix method is adopted. The dependence of reflectance and transmittance on the refractive index and thickness of NRIDL are analyzed in detail. Compared with the electroluminescence spectra of non-NRIDL diodes, the line widths of the spectra of the MOLEDs are narrower and all the peaks enhance. The results show that the new structure is beneficial to improve the performance and reduce the thickness of microcavity devices.展开更多
Novel molecular material, 1-benzotlliazoly-3 -phenyl --pyrazoline (BTPP) was found to function as bright blue light emitting dye in organic electroluminescent device, and its optical and electric characteristics were ...Novel molecular material, 1-benzotlliazoly-3 -phenyl --pyrazoline (BTPP) was found to function as bright blue light emitting dye in organic electroluminescent device, and its optical and electric characteristics were investigated. This heterocyclic compound exhibited good characteristics of blue photoluminescence and electroluminescence, which had the emission peak at 450 nm. The single layer light-emitting devices using BTPP as light-emitting material dispersed in poly(N- vinylcarbazole) (PVK) and double layer ones using PBD as hole block layer above the light-emitting layer were fabricated using conventional spin-casting and vaccum vapour deposition methods. The introduction of PBD has enhanced electron injection and luminance efficiency, compared with the single layer LEDs.展开更多
A blue dye, 1-benzqthiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photolu...A blue dye, 1-benzqthiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photoluminescence and electroluminescence, which has emission peak at 445 nm. The thin films of fluorescent dye dispersed in poly(N-vinylcarbazole) (PVK) could serve as light-emitting layers in multilayer organic LEDs. 2-(4-Biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and tris-(8-hydroxyquinoline) aluminum (Alq3) were introduced into double-layer and three-layer devices respectively. The introduction of electron transport material Alq3 enhanced the electron injection and luminous efficiency, as compared with double-layer devices. Maximum brightness and luminous efficiency can be reached up to 190 cd/m(2) and 0.31 m/W, respectively.展开更多
文摘Self-consistent ab initio calculations, based on the density functional theory （DFT） and using the full potential linear augmented plane wave （FLAPW） method, are performed to investigate both electronic and magnetic properties of the MnS layers. Polarized spin and spin-orbit coupling are included in the calculations within the framework of the antiferromagnetic state between two adjacent Mn layers. Magnetic moments considered to lie along axes are computed. Obtained data from ab initio calculations are used as input data for the high temperature series expansion （HTSE） calculations to compute other magnetic parameters. The zero-field high temperature static susceptibility series of the spin-4.39 nearest-neighbour Heisenberg model on centred face cubic （FCC） and lattices is thoroughly analysed by a power series coherent anomaly method （CAM）. The exchange interactions between the magnetic atoms, the N@el temperature, and the critical exponent associated with the magnetic susceptibility are obtained for the MnS layer.
基金Natural Science Research Item of Education Department of Henan Province(2008A430009)Doctor Foundation of Henan Polytechnic University(B2008-22)
文摘A new structure containing negative refractive index dielectric layer(NRIDL) is introduced into microcavity. The properties of the new microcavity organic light-emitting devices(MOLEDs) are investigated. In the experiment, the transfer matrix method is adopted. The dependence of reflectance and transmittance on the refractive index and thickness of NRIDL are analyzed in detail. Compared with the electroluminescence spectra of non-NRIDL diodes, the line widths of the spectra of the MOLEDs are narrower and all the peaks enhance. The results show that the new structure is beneficial to improve the performance and reduce the thickness of microcavity devices.
基金supported by the National "863" project !863 -307-05-05(02) National Natural Science foundation!69637010
文摘Novel molecular material, 1-benzotlliazoly-3 -phenyl --pyrazoline (BTPP) was found to function as bright blue light emitting dye in organic electroluminescent device, and its optical and electric characteristics were investigated. This heterocyclic compound exhibited good characteristics of blue photoluminescence and electroluminescence, which had the emission peak at 450 nm. The single layer light-emitting devices using BTPP as light-emitting material dispersed in poly(N- vinylcarbazole) (PVK) and double layer ones using PBD as hole block layer above the light-emitting layer were fabricated using conventional spin-casting and vaccum vapour deposition methods. The introduction of PBD has enhanced electron injection and luminance efficiency, compared with the single layer LEDs.
基金This work was supported by National Natural Science Foundation of China(No.69637010).
文摘A blue dye, 1-benzqthiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photoluminescence and electroluminescence, which has emission peak at 445 nm. The thin films of fluorescent dye dispersed in poly(N-vinylcarbazole) (PVK) could serve as light-emitting layers in multilayer organic LEDs. 2-(4-Biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and tris-(8-hydroxyquinoline) aluminum (Alq3) were introduced into double-layer and three-layer devices respectively. The introduction of electron transport material Alq3 enhanced the electron injection and luminous efficiency, as compared with double-layer devices. Maximum brightness and luminous efficiency can be reached up to 190 cd/m(2) and 0.31 m/W, respectively.
